Article Search Results

Show Filters
Showing 314 results for "*"
Iridescent arrowhead needles
Article
Characterization of Blue Sapphires from the Mogok Stone Tract, Mandalay Region, Burma (Myanmar)

The Mogok Stone Tract of central Myanmar (Burma) is one of the world’s most famed sources of colored stones, particularly ruby, sapphire, and spinel.

Read More

Accurate Reporting of Key Trace Elements in Ruby and Sapphire Using Matrix-Matched Standards

Presents a group of corundum standards developed by GIA to improve the accuracy and efficiency of its laser ablation–inductively coupled plasma–mass spectrometry (LA-ICP-MS) instruments.

Read More

Cat's-eye demantoid with well-aligned horsetail inclusions.
Cat's-Eye Demantoid and Brown Andradite with Horsetail Inclusions

The examination of two unusual garnets results in identifications issued for the first time in GIA's colored stone report records.

Read More

Experimental steps of DNA extraction and purification.
DNA Techniques Applied to the Identification of Pinctada Fucata Pearls from Uwajima, Ehime Prefecture, Japan

Shows how genetic material extracted from small amounts of pearl powder can be a useful indicator of this akoya cultured pearl species.

Read More

Rough and faceted natural-color green diamonds.
Natural-Color Green Diamonds: A Beautiful Conundrum

Characterizes diamonds with exceptionally rare natural green color, based on GIA’s extensive database of samples.

Read More

Orange pear-shaped pyrope-spessartine-grossular garnet.
Unusual Orange Pyrope-Spessartine-Grossular Garnet

A garnet proves to have a much higher grossular component than initially expected.

Read More

Strand of small akoya bead-cultured pearls.
Very Small Akoya Cultured Pearls

A selection of very small akoya cultured specimens demonstrates the challenges gemologists face when determining pearl origin.

Read More

Diamond and fraudulent inscription.
HPHT-Processed Diamond Fraudulently Represented as Untreated

An HPHT-treated round brilliant diamond with an inscription that presents as a GIA report number is found to be inconsistent with the institute's report, previously issued for an untreated diamond.

Read More

Article
DNA Techniques Applied to the Identification of Pinctada Fucata Pearls from Uwajima, Ehime Prefecture, Japan Supplementary Data

Shows how genetic material extracted from small amounts of pearl powder can be a useful indicator of this akoya cultured pearl species.

Read More

Article
Atypical “Beading” in the Production of Cultured Pearls from Australian Pinctada Maxima

In 2011, the authors began to see cases of low-quality natural pearls being used as unconventional “beads” for cultured nacre growth.

Read More